When Cathy Flanders, 41, of Plano, Texas, started burning candles for their pleasant smell in the spring of 1997, it never occurred to her she could be poisoning her family.

Three years, a serious illness, and a lawsuit later, Flanders has a lesson to share with anyone buying scented candles: Watch out for metal wicks. Lead emitted by this type of candle is a serious health hazard.

"Candles are fast becoming one of the most common unrecognized causes of poor indoor air quality," says Diane Walsh Astry of the Health House, a national education project created by the American Lung Association of Minnesota.

The Flanders' woes started when Cathy was shopping at a clothing store and spotted some candles whose labels promised to fill her house with the pleasant fragrances of "winter" and "spring." Within six months of burning the candles, she noticed soot damage around her house. But Cathy didn't pinpoint the source of the problem until after Ron Bailey of Bailey Engineering in Palm Beach Gardens, Fla., analyzed the Flanders' candles and discovered lead emissions.

Around that time, 11-year-old Andrew Flanders' grades dropped precipitously. His teacher wondered if he had attention deficit disorder. When blood tests revealed an elevated level of lead, the Flanders promptly sent him to live with his aunt.

"The lead deposits in our home are such that we could not sell the house if we wanted to," says Flanders. As for the candles, the doctor ordered a total ban. Testing revealed the lead level in the Flanders' home to be 40 milligrams per square foot -- 27 times the limit allowed in Housing and Urban Development homes.

Aromatherapy

The Flanders aren't the only ones falling victim to pleasant-smelling candles with toxic wicks. Candle sales in general have skyrocketed in recent years, according to the National Candle Association in Washington, D.C., from $500 million in 1995 to $2.3 billion in 1999. Part of the candle craze may be due to new interest in aromatherapy, a type of alternative medicine that uses odors to relax or treat illness.

Ironically, the very candles sometimes used for aromatherapy can cause serious health problems. The chief culprits are candles with wicks made with metal cores.

"Some candle makers use metal-core wicks because cotton wicks are often limp and fall over into the wax, extinguishing the flame," explains Jerome O. Nriagu, Ph.D., a professor of environmental chemistry at the University of Michigan in Ann Arbor who has studied scented candles.

Lead poisoning can lead to behavior changes and damage internal organs, especially the kidneys. Cathy's husband, Kip, had his gall bladder removed because of an illness he blames on the candles.

Metal Wicks

Nriagu measured the lead released from 14 brands of candles. He found that burning four metal-wick candles for two hours resulted in airborne lead concentrations that were dangerous to human health. People with weak immune systems, including children and the elderly, are particularly at risk.